When designing hydraulic structures, engineers follow a structured and predetermined set of design phases, referred to as the design process. Within this process, the preliminary design phase is a highly iterative process, which requires many calculations. From these calculations many different initial designs of the structure are derived. Generally, these possible configurations are compared to the design requirements. An important requirement is the safety of the structure over its lifetime. This can be reasonably accounted for by applying different reliability methods. Within these methods, different elements of uncertainty are considered. In the preliminary and final design stage, depending on the engineer, the quantification of these uncertainties and the safety of a structure during its service lifetime are often based on expert judgement, partial safety factors or are not considered at all. It is generally perceived that a full probabilistic approach gives more insights into the reliability and safety of the design. Due to the complex nature of this process and the mathematical workload, computer automated designs are becoming more popular. One possible automation method is the parametric design method, which translates different mathematical relations into parameters which can be easily altered. This research aims to develop a model which parametrically determines multiple solutions for a probabilistic design approach of a rubble mound slope protection, which takes into account uncertainty. This leads to an expansion and acceleration of the insight into possible design options in the preliminary design phase.